Jamaican police probing the murder of Pakistan's cricket coach Bob Woolmer say they could be searching for more than one attacker.

Police say Woolmer may have known his killer or killers, and are studying video footage from the Pegasus Hotel.

Members of the Pakistan team and staff have already been interviewed, and now plan to return home at the weekend.

Woolmer, who was 58, was strangled in his room hours after Pakistan lost to Ireland in the cricket World Cup.

The defeat dumped Pakistan - a talented but erratic team ranked fourth in the world - out of the competition.

A post-mortem examination established that the former England player had died as a result of "manual strangulation", police commissioner Lucius Thomas said.

"In these circumstances, the matter of Woolmer's death is now being treated as murder," he told a news conference.

Lines of inquiry

Suspicions that the coach may have known anyone who attacked him have been raised after it emerged there were no signs of forced entry at his hotel room in Kingston and none of his possessions were taken.

Woolmer was found unconscious by staff at the Pegasus Hotel on Sunday morning.

The deputy commissioner of the Jamaican police, Mark Shields, said this might now be a hunt for more than one killer, and urged the perpetrators to hand themselves in.

"Bob was a large man. It would have taken some significant force to subdue him," he said, adding that police were ruling nothing out and had "lots of lines of inquiry".

"I have to say at this stage that it looks as if it may be somebody who's somehow linked to him, because clearly he let somebody into his hotel room and it may be that he knew who that person was," Mr Shields told the BBC.

Mr Shields also "unequivocally dismissed" Indian television reports that arrests had been made.

"That's nonsense, as far as I'm concerned. There's actually no truth in that," he said.

The BBC's Andy Gallacher in Kingston says that Bob Woolmer's murder has stunned the cricketing world and left the World Cup in disarray.

Bob was a large man - it would have taken some significant force to subdue him